Ancient Sea Amphibian Discovery Rewrites History

Paleontologists have discovered fossilized remains in China's Guizhou Province of Gerrothorax maritimus, an amphibian that lived exclusively in the sea 237 million years ago during the Triassic Period. This previously unknown creature, measuring about 30 inches in length, existed before the age of dinosaurs and coexisted with marine reptiles like ichthyosaurs.

The discovery is significant because amphibians typically rely on permeable skin for breathing and hydration, a function compromised by saltwater. Gerrothorax maritimus, however, evolved body armor, a trait likely inherited from freshwater ancestors. This armor is believed to have protected it from osmotic water loss through its skin.

Researchers suggest Gerrothorax maritimus was a bottom-dwelling suction feeder, using its wide mouth to capture prey like fish and worms on the seafloor. Its bones show a chemical signature consistent with Triassic seawater, confirming its marine habitat rather than being washed out to sea after death.

This finding challenges the long-held scientific understanding that amphibians cannot survive in fully marine environments due to their skin's inability to cope with salt. Gerrothorax maritimus demonstrates a unique adaptation, repurposing traits for survival in a harsh environment.